Telescoping-type connectors for fluid lines and the like are well-known, one variety of such connector being sold by the Hansen Manufacturing Company of Cleveland Ohio, known as the "Hansen Connector". Examples of such connectors are illustrated in U.S. Pat. Nos. 2,518,542; 2,761,469; 3,245,423; and 3,351,362.
A typical embodiment of this type of connector utilizes inner and outer telescoping members in which the inner telescoping member sealingly fits within an aperture of the outer telescoping member to make the desired fluid line connection. The connection is held in retention by means of several spaced, metal balls which project through the wall of the aperture of the outer telescoping member, to fit into an outer circumferential groove of the inner member for retention thereof. The balls are held in their inwardly projecting, retaining position by an outer sleeve positioned on the outer member which presses the balls inwardly. To couple and decouple the connector, the outer sleeve is axially displaced to free the balls so that they may retract outwardly, in which position the inner telescoping member may slide into or out of the outer member.
The telescoping-type connectors are suitable for use in many different fields, including the field of disposable medical devices such as dialyzers or oxygenators for blood. While in the past the telescoping-type connectors have been made of metal such as brass, stainless steel or the like, it becomes desirable in the case of disposable devices such as those mentioned above to provide a telescoping-type connector in which at least one of the telescoping members, typically the inner member, is made of an inexpensive, molded plastic, so that the connector member does not have to be salvaged following use of the disposable device.
However, it has been found that some difficulties of molding such a connector member have been encountered. For example, it is often difficult to mold the inner telescoping member of a given size, because the relatively thick section of plastic between its outer circumferential groove and its forward end, which should be of precise dimensions, is subject to warpage, distortion, and sinking as the thick section of material cools. This results in a substantial number of parts which do not meet desired manufacturing specifications because of their tendency to leak.
However, if one removes plastic from the outer portion of the thick section, a second circumferential groove can be formed which acts in a manner similar to the functioning circumferential groove intended for receiving the balls of the outer telescoping member. If the second groove does so receive the retaining balls, the connector can assume an apparently locked configuration without being actually locked in sealing condition, so that leakage takes place.
The invention of this application provides an inner telescoping member in which the thick plastic section adjacent the forward end can be reduced to save plastic, and to avoid the undesirable distortions of the dimensions which often take place in molded, thick plastic sections, while at the same time reducing the possibility of falsely locked configuration which does not seal, because the retaining balls of the outer telescoping member are projecting into the wrong area of the inner telescoping member.
Accordingly, a disposable, telescoping-type connector member is provided in which the advantages of the connector can be combined with disposable equipment.